Harnessing synthetic microbial communities for desert vegetation restoration.

The core bottleneck for desert vegetation restoration is extreme water stress during early seedling establishment, with hydraulic failure as the primary lethal mechanism. Traditional engineering measures (e.g., irrigation) and single-strain inoculation cannot adequately address these challenges due to high cost, weak sustainability, or limited functionality. Synthetic microbial communities (SynComs) offer a new approach to synergistically regulate plant water use and soil microenvironment by integrating functionally complementary taxa. This review discusses the soil water characteristics of deserts and the bottlenecks in seedling water use, indigenous microbial resources and their adaptive mechanisms, principles and design strategies for constructing SynComs, as well as the mechanisms by which SynComs improve seedling water use efficiency and survival. We also analyze key challenges and future research directions. Although SynComs have been extensively studied for enhancing plant stress resistance, their application in desert vegetation restoration is still in its infancy. Future research needs to clarify how to design SynComs to ensure their ecological compatibility, persistence, and functionality in the highly variable and extreme environments of desertified landscapes. This review provides a theoretical basis for advancing SynComs application in arid land ecological restoration.